Food machinery for stuffing meat such as ham into a protective casing therefor to form a number of individual packages comprises a horn on which a considerable quantity of shirred casing is stored. The forward end of the casing is sealed, a quantity of meat is extruded through the horn into the casing, and the after end of the casing is sealed to complete a cycle. Generally it is required to extrude measured quantities of meat into a casing, and high speed machines such as described in my pending U.S. patent applications Ser. Nos. 539,575 or 757,999 titled MEAT PACKAGING APPARATUS employ a pneumatically operated ram to expel meat from the horn as part of the cyclic operation. At the beginning of each cycle using machines of this type, the horn is empty. Meat forced through the horn in the first step of a cycle for extrusion into the casing displaces the air from the horn. Where the casing is of a porous nature, this air may escape through the casing wall itself. Increasingly, advantage is being found in using barrier type casings which are substantially impermeable. When using such impermeable casings, the expelled air in this first step of the cycle must be exhausted between the outer wall of the horn and the casing stored thereon. In that the casing is only loosely fitted on the horn for storage purposes, the exhaust of air between the casing and horn does not create a problem. However, it is normally required that the meat be stuffed into the casing under pressure, and a tensioning device is employed to restrict the free movement of the casing from the horn under the influence of the meat being extruded into the casing. The pressure induced within the casing in this manner induces a backflow of meat between the outer surface of the horn and the casing mounted thereon. A backflow restrictor is provided to prevent such backflow. The backflow restrictor may be combined with the tensioning device, or it may be separate therefrom. In all events, the backflow restrictor functions to prevent the exhaust of the expelled air from the horn.
It is then a primary object of this invention to provide improved apparatus for stuffing casings.
It is another object of the invention to provide such apparatus which may have increased throughput.
It is yet another object of the invention to provide apparatus for use in connection with impermeable casings.
It is still another object of the invention to provide apparatus with an improved backflow restrictor.
It is a further object of the invention to provide a method which is particularly adapted for high speed stuffing of impermeable casings to provide individual packages.